WO2010079619A1 - Dispositif de purification de gaz d’échappement pour moteurs à combustion interne - Google Patents

Dispositif de purification de gaz d’échappement pour moteurs à combustion interne Download PDF

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Publication number
WO2010079619A1
WO2010079619A1 PCT/JP2009/050251 JP2009050251W WO2010079619A1 WO 2010079619 A1 WO2010079619 A1 WO 2010079619A1 JP 2009050251 W JP2009050251 W JP 2009050251W WO 2010079619 A1 WO2010079619 A1 WO 2010079619A1
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Prior art keywords
nox
amount
exhaust gas
internal combustion
desorption
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PCT/JP2009/050251
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English (en)
Japanese (ja)
Inventor
文悟 川口
鴨下　伸治
小田　富久
大橋　伸基
智志 小早川
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トヨタ自動車株式会社
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Priority to JP2010545675A priority Critical patent/JP5158214B2/ja
Priority to EP09837506.6A priority patent/EP2386735B1/fr
Priority to PCT/JP2009/050251 priority patent/WO2010079619A1/fr
Publication of WO2010079619A1 publication Critical patent/WO2010079619A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0842—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
    • F01N3/2033—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using a fuel burner or introducing fuel into exhaust duct
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066—Selective catalytic reduction [SCR]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N9/00—Electrical control of exhaust gas treating apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/06—Parameters used for exhaust control or diagnosing
    • F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
    • F01N2900/1602—Temperature of exhaust gas apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/06—Parameters used for exhaust control or diagnosing
    • F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
    • F01N2900/1621—Catalyst conversion efficiency
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • the present invention relates to an exhaust purification device for an internal combustion engine.
  • a NOx catalyst for purifying nitrogen oxide (NOx) contained in exhaust gas is known as an exhaust purification device disposed in an exhaust system of an internal combustion engine such as a diesel engine.
  • NOx catalysts Various types of NOx catalysts are known, and among them, selective reduction type catalysts that continuously reduce and remove NOx by adding a reducing agent are known.
  • the reducing agent urea water or ammonia is known.
  • urea water mixed with water at a predetermined ratio is injected and supplied into exhaust gas upstream of the catalyst, and urea contained in the urea aqueous solution is hydrolyzed by heat of the exhaust gas or the like to generate ammonia.
  • NOx in the exhaust gas is purified by the reducing action of ammonia that removes oxygen from NOx and returns it to nitrogen on the selective catalytic reduction catalyst (see, for example, Patent Documents 1 to 3).
  • the temperature of the selective catalytic reduction catalyst does not reach the activation temperature, and in this state, NOx generated in the internal combustion engine is released to the outside without being purified.
  • a NOx adsorbent that temporarily adsorbs NOx is provided on the upstream side of the selective catalytic reduction catalyst. While the selective catalytic reduction catalyst is not activated, the NOx adsorbent adsorbs NOx.
  • a technique for detaching NOx from the NOx adsorbent while the selective reduction catalyst is activated has been proposed.
  • the selective reduction catalyst may not be able to completely purify NOx, and a part of the NOx that is not purified may be released to the outside. There is.
  • the present invention has been made in view of the above circumstances, and the object of the present invention is that NOx is not purified by the selective catalytic reduction regardless of whether the selective catalytic reduction is activated or deactivated.
  • An object of the present invention is to provide an exhaust purification device for an internal combustion engine that can suppress slipping and improve the NOx purification rate.
  • An exhaust gas purification apparatus for an internal combustion engine includes an NOx adsorbent provided in an exhaust passage of the internal combustion engine for temporarily adsorbing NOx contained in exhaust gas, and an NOx adsorbent in the exhaust passage.
  • a selective reduction catalyst that is provided downstream and selectively reduces NOx contained in exhaust gas, a reducing agent supply means that supplies ammonia as a reducing agent to the selective reduction catalyst, and is adsorbed by the NOx adsorbent.
  • the desorption means for desorbing NOx and the purification rate of the selective catalytic reduction catalyst and the desorption means to suppress the release of NOx to the outside when desorbing NOx from the NOx adsorbent.
  • adjusting means for adjusting at least one of the NOx desorption amounts.
  • the exhaust gas purification apparatus for an internal combustion engine according to the second aspect of the present invention further includes NOx amount estimating means for estimating the amount of NOx desorbed from the NOx adsorbent by the desorbing means, and the adjusting means is the NOx amount.
  • the amount of reducing agent to be supplied to the selective catalytic reduction catalyst is adjusted according to the amount of NOx estimated by the estimating means.
  • the exhaust gas purification apparatus for an internal combustion engine according to the second aspect of the present invention further includes ammonia adsorption amount estimation means for estimating the ammonia adsorption amount adsorbed on the selective reduction catalyst, and the adjustment means includes the estimated NOx.
  • a configuration in which the amount of reducing agent to be supplied to the selective catalytic reduction catalyst is adjusted according to the amount and the estimated ammonia adsorption amount can be employed.
  • the exhaust gas purification apparatus for an internal combustion engine further includes an ammonia amount estimating means for estimating the amount of ammonia adsorbed on the selective catalytic reduction catalyst, and the adjusting means comprises the estimated ammonia
  • the amount of NOx desorption by the desorption means is adjusted according to the amount of adsorption.
  • the desorption means can adopt a configuration that adjusts the NOx desorption amount by controlling the temperature of the NOx adsorbent.
  • the NOx desorption amount is adjusted by utilizing the NOx adsorbable amount that changes according to the temperature of the NOx adsorbent.
  • the desorbing means includes a burner that is provided upstream of the NOx adsorbent in the exhaust passage, and jets combustion gas into the exhaust passage, and the adjusting means controls the amount of heat discharged by the burner.
  • the selective catalytic reduction catalyst regardless of whether the selective catalytic reduction catalyst is activated or deactivated, it is possible to improve the NOx purification rate by suppressing the selective catalytic reduction without passing through the selective catalytic reduction catalyst.
  • FIG. 1 is a diagram showing a configuration of an exhaust emission control device for an internal combustion engine according to an embodiment of the present invention.
  • FIG. 2 is a flowchart showing an example of NOx desorption processing according to an embodiment of the present invention.
  • FIG. 3 is a diagram for explaining an example of a map for estimating the NOx emission amount.
  • FIG. 4 is a graph showing the relationship between the catalyst bed temperature of the selective reduction catalyst and the maximum adsorption amount of ammonia that can be adsorbed on the selective reduction catalyst.
  • FIG. 5 is a flowchart showing an example of a NOx purification rate adjustment process according to an embodiment of the present invention.
  • FIG. 6 is a diagram for explaining an example of a map for determining the NOx purification rate.
  • FIG. 1 is a diagram showing a configuration of an exhaust emission control device for an internal combustion engine according to an embodiment of the present invention.
  • FIG. 2 is a flowchart showing an example of NOx desorption processing according to an embodiment of the present invention.
  • FIG. 7 is a flowchart showing an example of NOx desorption amount adjustment processing according to an embodiment of the present invention.
  • FIG. 8 is a diagram for explaining an example of a map for obtaining a NOx purification amount that can be purified from the estimated ammonia adsorption amount.
  • FIG. 9 is a diagram for explaining an example of a map for obtaining a correction coefficient for correcting the NOx purification amount obtained in FIG.
  • FIG. 10 is a diagram for explaining a method of controlling the NOx release amount by adjusting the temperature of the NOx adsorbent.
  • FIG. 1 is a configuration diagram of an exhaust emission control device for an internal combustion engine according to an embodiment of the present invention.
  • the internal combustion engine 10 is, for example, a diesel engine.
  • a burner 20 as a desorption means
  • an adsorbent 25 capable of adsorbing NOx
  • PM partate matter contained in the exhaust gas EG are collected in order from the upstream side.
  • a DPF (diesel particulate filter) 30, a selective catalytic reduction converter 40 and an oxidation catalytic converter 50 are provided.
  • an exhaust temperature sensor 60A In the exhaust passage 15, between the burner 20 and the NOx adsorbent 25, an exhaust temperature sensor 60A, between the NOx adsorbent 25 and the DPF 30, between the exhaust temperature sensor 60B and the DPF 30 and the selective catalytic reduction converter 40.
  • An exhaust gas temperature sensor 60C is provided on the upstream side and an exhaust gas temperature sensor 60D is provided on the downstream side.
  • the outputs of the exhaust gas temperature sensors 60A to 60D are input to an electronic control unit (ECU) 100.
  • ECU electronice control unit
  • a NOx sensor 65A is provided upstream of the selective catalytic reduction converter 40, and a NOx sensor 65B is provided downstream of the oxidation catalytic converter 50.
  • the outputs of these NOx sensors 65A and 65B are electronic control units (ECUs). 100 is input.
  • a urea water addition valve 70 as a reducing agent supply means for adding a urea aqueous solution to the exhaust passage 15, and downstream of the urea water addition valve 70.
  • An addition valve downstream mixer 80 for mixing the exhaust gas EG and the urea aqueous solution is provided.
  • the urea water addition valve 70 is connected to a urea water tank 71 that stores urea water of a predetermined concentration.
  • the urea water tank 71 is provided with a pump (not shown) and supplies urea water to the urea water addition valve 70 in accordance with a control command from the ECU 100.
  • the urea water addition valve 70 adds an addition amount of urea water 90 according to a control command from the ECU 100 to the exhaust passage 15.
  • the burner 20 is connected to the internal combustion engine 10, a fuel supply pipe 16 that supplies fuel, and an air supply pipe 17 that supplies air, and a fuel injection valve that injects fuel toward the exhaust passage 15, air from the air supply pipe 17. Is formed from an air inlet for supplying the gas toward the exhaust passage 15 and an ignition plug for igniting the fuel injected from the fuel injection valve and mixed with the air.
  • the start and stop of the burner 20 are controlled by the ECU 100.
  • the fuel is combusted, the combustion gas is supplied to the exhaust passage 15, the temperature of the exhaust gas EG rises, and unburned fuel is supplied into the exhaust passage 15.
  • the burner 20 can supply a gas obtained by completely burning the fuel into the exhaust passage 15, or can supply the burned gas into the exhaust passage 15 with unburned fuel mixed with the burned gas.
  • the NOx adsorbent 25 can temporarily adsorb and hold nitrogen oxides (NOx). As will be described later, this NOx adsorbent 25 has a characteristic that the amount of NOx that can be adsorbed changes according to its temperature.
  • the NOx adsorbent 25 is made of a known adsorbent material such as zeolite, for example.
  • the DPF 30 is a filter that collects particulate matter (PM) contained in the exhaust gas EG.
  • the structure of the DPF 30 is composed of, for example, a honeycomb body made of metal or ceramics.
  • PM particulate matter
  • the DPF 30 needs to be heated to the activation temperature or higher by using the burner 20, burn the collected PM, and regenerate the filter function.
  • the temperature of the DPF 30 in this regeneration process is, for example, about 600 to 700 ° C. Note that the determination of whether a predetermined amount of PM has accumulated on the DPF 30 is a well-known technique, and a description thereof will be omitted.
  • the selective reduction catalytic converter 40 selectively reduces NOx contained in the exhaust gas EG into nitrogen gas and water using the urea aqueous solution added from the urea addition valve 70 as a reducing agent. Specifically, the urea aqueous solution added to the exhaust gas EG is hydrolyzed by the heat of the exhaust gas EG to change to ammonia, and this ammonia reacts with NOx in the catalytic converter 40 to form water and harmless nitrogen. Be reduced.
  • the selective catalytic reduction converter 40 has a well-known structure, for example, a material composed of zeolite containing Si, O, and Al as main components and containing Fe ions, or a surface of a base material made of, for example, aluminum oxide alumina.
  • a catalyst in which a selective reduction catalyst such as a vanadium catalyst (V 2 O 5 ) is supported on a substrate can be used, and the present invention is not particularly limited thereto.
  • the selective reduction catalytic converter 40 has an activation temperature that functions as a catalyst of, for example, about 200 ° C. or more, and if NOx is supplied without reaching the activation temperature, it may be discharged outside without being reduced. There is.
  • the oxidation catalytic converter 50 serves to oxidize unburned fuel and ammonium that pass through the selective catalytic reduction converter 40.
  • the oxidation catalytic converter 50 has a known structure.
  • the ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electronically Erasable and Programmable Read Only Memory Converter, etc.). It comprises hardware including an output interface circuit including an input interface circuit, a drive circuit, etc., and necessary software.
  • the ECU 100 controls the burner 20, the urea water addition valve 70 and the like based on signals from the exhaust temperature sensors 60A to 60D and the NOx sensors 65A and 65B. Specific processing by the ECU 100 will be described later.
  • exhaust gas EG containing NOx and PM is discharged from the internal combustion engine 10.
  • NOx contained in the exhaust gas EG is adsorbed by the NOx adsorbent 25.
  • PM contained in the exhaust gas EG is collected by the DPF 30.
  • the amount of NOx adsorbed by the NOx adsorbent 25 and the amount of PM collected by the DPF 30 increase.
  • urea water 90 is added from the urea water addition valve 70, which is hydrolyzed by the heat of the exhaust gas EG and the like to generate ammonia.
  • This ammonia is selectively reduced by the selective catalytic reduction converter 40. Adsorbed on the mold catalyst.
  • the selective catalytic reduction catalyst is changed from the inactivated state to the activated state by heat of the exhaust gas EG or the like, purification of NOx contained in the exhaust gas EG is started.
  • the selective catalytic reduction catalyst is activated, the NOx passing through the NOx adsorbent 25 without being adsorbed by the NOx adsorbent 25 is purified by the selective catalytic reduction catalyst.
  • step S1 it is determined whether the NOx adsorption amount of the NOx adsorbent 25 exceeds a predetermined threshold value Th (step S1).
  • the NOx adsorption amount of the NOx adsorbent 25 is estimated using, for example, a map of NOx emission amount defined by the relationship between the fuel injection amount and the engine speed in the internal combustion engine 10 as shown in FIG.
  • the integrated value of the NOx emission amount obtained from this NOx map is the estimated value of the NOx adsorption amount of the NOx adsorbent 25.
  • the NOx adsorbent 25 has a characteristic that its maximum NOx adsorbed amount changes according to the temperature of the NOx adsorbent 25, for example, as shown in FIG. That is, the maximum adsorption amount of the NOx adsorbent 25 is defined according to the temperature. Therefore, as shown in FIG. 4, the threshold Th defined in a range not exceeding the maximum adsorption amount according to the temperature of the NOx adsorbent 25 is compared with the estimated value of the NOx adsorption amount, and the NOx adsorption amount is compared. If the estimated value does not exceed the threshold value Th, the process is terminated.
  • the following process is executed in order to execute the desorption process of NOx from the NOx adsorbent 25.
  • step S2 it is determined whether the driving state of the vehicle is in a deceleration state (step S2). If the vehicle is not in a deceleration state, it is determined whether the vehicle is in an idling operation (step S3). The reason for executing such a determination will be described later.
  • Step S4 when the driving state of the vehicle is a deceleration state or an idling operation, it is determined whether the selective catalytic reduction catalyst has exceeded the activation temperature (Step S4). This is because when the selective catalytic reduction catalyst has not reached the activation temperature, NOx is not purified by the selective catalytic reduction catalyst and may pass through.
  • step S4 if the selective catalytic reduction catalyst has not reached the activation temperature, the process is terminated, and if it has reached, the combustion gas is ejected from the burner 20 to the exhaust passage 15, and the temperature of the NOx adsorbent 25 is reached. Is raised above the NOx release temperature, and NOx is desorbed from the NOx adsorbent 25 (step S5). Thereby, the NOx desorbed from the NOx adsorbent 25 is purified in the selective reduction catalyst.
  • the NOx adsorption amount of the NOx adsorbent 25 when the NOx adsorption amount of the NOx adsorbent 25 is managed using the NOx emission amount map as shown in FIG. 3, the amount of heat released by the burner 20 necessary for the temperature rise of the NOx adsorbent 25 becomes the exhaust gas amount. Since it depends on the amount of heat and the exhaust gas temperature, especially when the amount of gas is large and the exhaust temperature is relatively low, the energy consumed by the burner 20 increases, leading to deterioration of fuel consumption. For this reason, the NOx desorption process from the NOx adsorbent 25 is limited to when the vehicle is in a decelerating state or idling operation. Thereby, in particular, it is possible to ensure the NOx adsorption capability at the time of acceleration at which the NOx emission amount increases, and to suppress deterioration in fuel consumption to a minimum.
  • the NOx purification rate is the ratio of NOx purified by the selective reduction catalytic converter 40
  • the NOx purification rate is, for example, NOx sensors 65A provided on the upstream side and the downstream side of the selective reduction catalytic converter 40. It can be obtained from the output of 65B.
  • step S11 it is determined whether or not to release (desorb) NOx adsorbed on the NOx adsorbent 25 (step S11). This determination is the same as steps S1 to S4 described in FIG. It is also possible to determine by a process other than the process of FIG.
  • step S11 if NOx release is not necessary, the process is terminated, and if necessary, the amount of NOx released when NOx desorption from the NOx adsorbent 25 is executed is estimated. .
  • the estimation of the NOx amount can be estimated from the current NOx adsorption amount of the NOx adsorbent 25.
  • a NOx purification rate for purifying NOx released from the NOx adsorbent 25 is calculated (step S13). That is, the amount of NOx to be purified by the selective reduction catalyst temporarily increases, and accordingly, the purification rate of the selective reduction catalyst is increased accordingly.
  • the purification rate of the selective catalytic reduction catalyst can be determined using, for example, a NOx purification rate map as shown in FIG.
  • the NOx purification rate map shown in FIG. 6 is defined in advance according to the catalyst temperature of the selective reduction catalyst and the amount of NOx discharged toward the reduction catalyst.
  • the urea water addition amount necessary for the NOx purification rate calculated in step S13 is calculated (step S14).
  • the necessary urea water addition amount can be calculated based on the NOx amount to be discharged, the determined NOx purification rate, and the estimated value of the ammonia adsorption amount already adsorbed on the selective catalytic reduction catalyst.
  • the estimation of the ammonia adsorption amount already adsorbed on the selective catalytic reduction catalyst can be calculated from the integrated value of the urea water addition amount, the integrated value of the NOx purification amount, and the like. Note that the method for estimating the ammonia adsorption amount already adsorbed on the selective catalytic reduction catalyst is a well-known technique and will not be described in detail. Therefore, since the urea water addition amount is increased or decreased according to the estimated ammonia adsorption amount, excessive addition of urea water can be prevented.
  • the urea water addition valve 70 is controlled to adjust the urea water addition amount (step S15). That is, when the NOx purification rate at the normal time cannot completely purify the NOx amount discharged toward the reduction catalyst, the urea water addition amount is increased.
  • the processing routine of FIG. 7 is executed at predetermined time intervals, for example. Further, the NOx desorption amount adjustment process of FIG. 7 can be used together with the NOx purification rate adjustment process described with reference to FIG. 5, or the NOx desorption amount adjustment process can be executed alone.
  • step S21 it is determined whether or not to release (desorb) NOx adsorbed on the NOx adsorbent 25 (step S21). This determination is the same as steps S1 to S4 described in FIG. It is also possible to determine by a process other than the process of FIG.
  • step S11 if NOx release is not necessary, the process is terminated, and if necessary, the amount of ammonia adsorbed on the selective catalytic reduction catalyst is estimated (step S22).
  • the method for estimating the ammonia adsorption amount is the same as the method described above.
  • the amount of NOx that can be purified is calculated based on the estimated ammonia adsorption amount (step S23).
  • the amount of NOx that can be purified can be determined, for example, using a NOx purification amount map that is defined according to the estimated ammonia adsorption amount and the catalyst temperature of the selective catalytic reduction catalyst, as shown in FIG.
  • purification can be performed by calculating a correction coefficient obtained from a correction coefficient map defined according to the intake air amount to the intake system of the internal combustion engine 10 and the catalyst temperature of the selective reduction catalyst.
  • the target temperature of the NOx adsorbent 25 for separating the NOx having a purifiable NOx amount calculated in step S23 is determined (step S24).
  • the maximum NOx adsorption amount of the NOx adsorbent 25 varies depending on the temperature.
  • T1 is the temperature before NOx is released, that is, the temperature before temperature adjustment, when the temperature of the NOx adsorbent 25 is increased to T2, the amount of NOx released becomes AM.
  • the burner 20 is controlled so that the temperature of the NOx adsorbent 25 becomes the target temperature T2 obtained in step S24.
  • the temperature of the NOx adsorbent 25 can be adjusted by controlling the amount of heat discharged from the burner 20. By controlling the temperature of the NOx adsorbent 25, a desired amount of NOx is desorbed from the NOx adsorbent 25, and this is reliably purified in the selective reduction catalyst.
  • the burner 20 is exemplified as the desorbing means.
  • the burner 20 is not limited to this.
  • the NOx adsorbent 25 is also provided with an oxidation catalyst function, and fuel is supplied to this for burning.
  • NOx can be desorbed.
  • the fuel may be supplied by using a dedicated fuel injection valve or by so-called post injection in the internal combustion engine 10.
  • the urea water addition valve is exemplified as the reducing agent supply means, but the present invention is not limited to this, and ammonia can be directly supplied to the selective reduction catalyst.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

L’invention concerne un dispositif de purification de gaz d’échappement pour des moteurs à combustion interne permettant d'améliorer le taux de purification de NOx en empêchant la libération de Nox n'ayant pas été purifiés par un catalyseur de type à réduction sélective, que le catalyseur de type à réduction sélective soit actif ou inactif. Le dispositif est équipé d’une substance d’adsorption de Nox (25) qui adsorbe temporairement les NOx, d’un catalyseur de type à réduction sélective (40) qui est disposé en aval de la substance d'adsorption de Nox dans un passage d'échappement (15) et qui réduit de manière sélective les Nox contenus dans le gaz d'échappement, d’une soupape d'addition de solution d'urée (70) qui fournit de l'ammoniac comme agent réducteur au catalyseur de réduction sélective, et d’un brûleur (20) qui retire les Nox adsorbés sur la substance d'adsorption de Nox. Le dispositif est conçu de manière à permettre d’ajuster le taux de purification du catalyseur de type à réduction sélective et/ou la quantité de retrait de Nox grâce au brûleur (20) afin de limiter la libération de Nox vers l'extérieur lorsque les Nox sont retirés de la substance d'adsorption de Nox.
PCT/JP2009/050251 2009-01-09 2009-01-09 Dispositif de purification de gaz d’échappement pour moteurs à combustion interne WO2010079619A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2010545675A JP5158214B2 (ja) 2009-01-09 2009-01-09 内燃機関の排気浄化装置
EP09837506.6A EP2386735B1 (fr) 2009-01-09 2009-01-09 Dispositif de purification de gaz d'échappement pour un moteur à combustion interne
PCT/JP2009/050251 WO2010079619A1 (fr) 2009-01-09 2009-01-09 Dispositif de purification de gaz d’échappement pour moteurs à combustion interne

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012117511A (ja) * 2010-12-02 2012-06-21 Hyundai Motor Co Ltd 窒素酸化物低減触媒に貯蔵される窒素酸化物の量を予測する方法及びこれを用いた排気装置
JP2015102088A (ja) * 2013-11-22 2015-06-04 現代自動車株式会社 排気ガス浄化装置および排気ガス浄化方法
JP2016050523A (ja) * 2014-08-29 2016-04-11 日野自動車株式会社 排気浄化システム
JP2016089699A (ja) * 2014-11-04 2016-05-23 本田技研工業株式会社 内燃機関の排気浄化装置
JP2016109097A (ja) * 2014-12-10 2016-06-20 日野自動車株式会社 排気浄化装置
US20180216510A1 (en) * 2017-01-30 2018-08-02 Ford Global Technologies, Llc Exhaust gas aftertreatment
US10519829B2 (en) 2016-02-22 2019-12-31 Hino Motors, Ltd. Exhaust purification system
JP2021500218A (ja) * 2017-10-20 2021-01-07 ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフトＵｍｉｃｏｒｅ ＡＧ ＆ Ｃｏ．ＫＧ 受動的窒素酸化物吸着剤触媒

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000230414A (ja) * 1999-02-09 2000-08-22 Ford Global Technol Inc 窒素酸化物吸収材を用いたディーゼル・エンジンからの排気の変換方法
JP2001182525A (ja) * 1999-12-22 2001-07-06 Toyota Central Res & Dev Lab Inc プラズマ下ｎｏｘ浄化方法及びその装置
JP2003286827A (ja) * 2002-03-28 2003-10-10 Nissan Diesel Motor Co Ltd 内燃機関の排気浄化装置
WO2004018850A1 (fr) 2002-08-26 2004-03-04 Hitachi, Ltd. Appareil et procede destines a purifier un gaz d'echappement de moteur diesel
JP2006112313A (ja) 2004-10-14 2006-04-27 Yanmar Co Ltd 排気ガス浄化装置及びその制御方法
JP2006342735A (ja) 2005-06-09 2006-12-21 Mitsubishi Fuso Truck & Bus Corp 排気浄化装置
JP2006342734A (ja) * 2005-06-09 2006-12-21 Mitsubishi Fuso Truck & Bus Corp 排気浄化装置
JP2008261253A (ja) * 2007-04-11 2008-10-30 Isuzu Motors Ltd ＮＯｘ浄化システム及びＮＯｘ浄化システムの制御方法
JP2008298036A (ja) * 2007-06-04 2008-12-11 Yanmar Co Ltd 排気ガス浄化装置

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7213395B2 (en) * 2004-07-14 2007-05-08 Eaton Corporation Hybrid catalyst system for exhaust emissions reduction
JP4792424B2 (ja) * 2007-05-11 2011-10-12 トヨタ自動車株式会社 内燃機関の排気浄化装置

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000230414A (ja) * 1999-02-09 2000-08-22 Ford Global Technol Inc 窒素酸化物吸収材を用いたディーゼル・エンジンからの排気の変換方法
JP2001182525A (ja) * 1999-12-22 2001-07-06 Toyota Central Res & Dev Lab Inc プラズマ下ｎｏｘ浄化方法及びその装置
JP2003286827A (ja) * 2002-03-28 2003-10-10 Nissan Diesel Motor Co Ltd 内燃機関の排気浄化装置
WO2004018850A1 (fr) 2002-08-26 2004-03-04 Hitachi, Ltd. Appareil et procede destines a purifier un gaz d'echappement de moteur diesel
JP2006112313A (ja) 2004-10-14 2006-04-27 Yanmar Co Ltd 排気ガス浄化装置及びその制御方法
JP2006342735A (ja) 2005-06-09 2006-12-21 Mitsubishi Fuso Truck & Bus Corp 排気浄化装置
JP2006342734A (ja) * 2005-06-09 2006-12-21 Mitsubishi Fuso Truck & Bus Corp 排気浄化装置
JP2008261253A (ja) * 2007-04-11 2008-10-30 Isuzu Motors Ltd ＮＯｘ浄化システム及びＮＯｘ浄化システムの制御方法
JP2008298036A (ja) * 2007-06-04 2008-12-11 Yanmar Co Ltd 排気ガス浄化装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2386735A4 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012117511A (ja) * 2010-12-02 2012-06-21 Hyundai Motor Co Ltd 窒素酸化物低減触媒に貯蔵される窒素酸化物の量を予測する方法及びこれを用いた排気装置
US9133746B2 (en) 2010-12-02 2015-09-15 Hyundai Motor Company Method for predicting NOx loading at DeNOx catalyst and exhaust system using the same
EP2461000A3 (fr) * 2010-12-02 2016-03-23 Hyundai Motor Company Procédé pour prédire une charge de NOx au niveau du catalyseur de DeNOx et système d'échappement l'utilisant
JP2015102088A (ja) * 2013-11-22 2015-06-04 現代自動車株式会社 排気ガス浄化装置および排気ガス浄化方法
JP2016050523A (ja) * 2014-08-29 2016-04-11 日野自動車株式会社 排気浄化システム
JP2016089699A (ja) * 2014-11-04 2016-05-23 本田技研工業株式会社 内燃機関の排気浄化装置
JP2016109097A (ja) * 2014-12-10 2016-06-20 日野自動車株式会社 排気浄化装置
US10519829B2 (en) 2016-02-22 2019-12-31 Hino Motors, Ltd. Exhaust purification system
US20180216510A1 (en) * 2017-01-30 2018-08-02 Ford Global Technologies, Llc Exhaust gas aftertreatment
US10690029B2 (en) * 2017-01-30 2020-06-23 Ford Global Technologies, Llc System and method for exhaust gas aftertreatment with lean NOx trap and exhaust gas recirculation
JP2021500218A (ja) * 2017-10-20 2021-01-07 ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフトＵｍｉｃｏｒｅ ＡＧ ＆ Ｃｏ．ＫＧ 受動的窒素酸化物吸着剤触媒
JP7244501B2 (ja) 2017-10-20 2023-03-22 ユミコア・アクチエンゲゼルシャフト・ウント・コムパニー・コマンディットゲゼルシャフト 受動的窒素酸化物吸着剤触媒

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EP2386735B1 (fr) 2015-09-16
JP5158214B2 (ja) 2013-03-06
EP2386735A1 (fr) 2011-11-16
JPWO2010079619A1 (ja) 2012-06-21
EP2386735A4 (fr) 2014-05-07

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